Sometimes it will/Sometimes it won't. HELP

Occasionally my ‘99’ suburban will not start and acts as if it is not getting fuel. First time this happened it had been sitting all night and would not start first thing. Called a tow truck. By the time it reached the shop, it started. Computer diagnosis found nothing. OK for several weeks. Next time had been driven a short ways and left to sit about twenty minutes, won’t start. Called a tow truck, but before it arrived tried it again, it started. (cancelled tow). I have left the truck with my mechanic for days so it could be driven and they could try to start it, etc. etc… Cannot duplicate, but still happens occasionally. Any ideas?

Tell your mechanic some know-it all on the net has had experience with intermittent fuel pump failure on this model.

Has your mechanic been able to decide if it is fuel or spark related?

Really the fuel pumps are know to exibit intermittent function but don’t let my information about a common known problem stop the normal diagnostic activity that should be done.

The fuel pump module assembly, fuel pump relay and fuel filter have all been replaced and the problem continues (only when I have the car, never when the mechanic has it). Engine performance analysis OK (always when mechanic has it). It sometimes runs for weeks before the problem resurfaces. Leave it alone for a while and it will start. ???

Hang a fuel pressure gauge on it. Tie it down carefully under the hood and make sure it doesn’t leak. Check the gauge next time it misbehaves. It could still be a faulty connector or wire in the fuel pump circuit. If that’s not it check for spark next time it fails.

Without revealing too much, I am an old woman with a cane and no tools or knowledge of a car (well, not much anyway). How do I do these things when it has me stranded somewhere? By the time I can get it to my mechanic it is not having a problem.